1. Field of the Invention
The present invention relates to a liquid cartridge.
2. Description of Related Art
A known ink jet recording apparatus is configured to record an image on a recording medium by ejecting ink stored in an ink container from nozzles. The viscosity of ink stored in the ink container may change over time. A known ink-jet recording apparatus, as described in Patent Application Publication No. JP-09-277560 A, is configured to estimate the viscosity of ink stored in an ink container, and perform optimized preliminary ejection based on the result of the estimation. More specifically, the ink-jet recording apparatus is configured to estimate the viscosity of ink based on an elapsed time since the ink container is mounted to the ink-jet recording apparatus and an amount of ink remaining in the ink container. Nevertheless, this known ink-jet recording apparatus does not estimate the viscosity by directly measuring a physical quantity obtained when ink moves in the ink container. Moreover, this known ink-jet recording apparatus cannot estimate the viscosity of ink stored in an ink container which has not been mounted to the ink-jet recording apparatus and been unused.